Subject: [TLS] Protocol Action: 'Deprecating TLSv1.0 and TLSv1.1' to Best Current Practice (draft-ietf-tls-oldversions-deprecate-12.txt)

From: The IESG <[email-masked]>
Date: Mon, 25 Jan 2021 09:11:49 -0800

The IESG has approved the following document:
- 'Deprecating TLSv1.0 and TLSv1.1'
  (draft-ietf-tls-oldversions-deprecate-12.txt) as Best Current Practice

This document is the product of the Transport Layer Security Working Group.

The IESG contact persons are Benjamin Kaduk and Roman Danyliw.

A URL of this Internet Draft is:
https://datatracker.ietf.org/doc/draft-ietf-tls-oldversions-deprecate/

Technical Summary

This document formally deprecates Transport Layer Security (TLS)
versions 1.0 [RFC2246], TLS 1.1 [RFC4346], and DTLS 1.0 [RFC4347].
It moves these documents to the historic state.  The draft is intended
for BCP because it updates 7525 and hence should be part of BCP195.

Working Group Summary

When this draft was first presented at IETF 102, there was
discussion about waiting to request publication until the
TLSv1.0 and TLSv1.1 use rates to drop to an “acceptable”
level.  There were others that felt that there was no need to
wait and that the IETF should do what it thinks is right with
its protocols.  The WG, obviously, settled on progressing this
draft.  Note this draft was further discussed at IETF 103 and
104 to resolve comments received.

There was also some discomfort from enterprise users who
were concerned about the time and expense needed to
transition to newer versions.  It should be noted that library
support typically continues for years beyond the publication
date of the RFC, e.g., OpenSSL released in Fall 2018 will
support TLSv1.0 and TLSv1.1 for roughly another 4 years.

The WGLC  [0] did produce some fireworks.  One participant
very strongly believes that “Disabling TLSv1.0 will only result
in lots of interop failures and pain, but no improvement in
security”.  The assertion was that the use of (RSA,MD) and
(RSA,SHA-1) is allowed in TLS 1.2.  This comment resulted in
draft-lvelvindron-tls-md5-sha1-deprecate, which deprecates
the use of MD5 and SHA1 in TLS1.2.  The chairs determined
that this draft could proceed without the MD5/SHA1 deprecation
text as it is contained in another draft [1].

IETF LC also added two RFCs to the updates list and more
importantly a section was added to address operational
considerations.

[0] Link to WGLC thread:
https://mailarchive.ietf.org/arch/msg/tls/cupb-OgiSK1ulpRANAbihPHc7zI
[1] Link to chair msg:
https://mailarchive.ietf.org/arch/msg/tls/xyMXqKQUZeztD5WupvI0uBp4OLA

Document Quality

The document got a great deal of review from many people.
The list of documents updated was produced mechanically with a
script and is believed to be accurate and complete.
Implementations have started picking up the guidance to greater
and lesser extent, but the only interoperability considerations are
expected to be those listed in the operational considerations section
of the document, since the change is just to remove support (whether
entirely or by default) for the older protocol versions.

Personnel

The document shepherd is Sean Turner.
The Area Director is Benjamin Kaduk.